Pre-order Now does not yet have a feature to apply pre-order settings to all products in a collection. We do have a workaround though.
To turn on pre-order for all products in a collection, please:
- Add a tag to all products in the collection you'd like to enable for pre-order (e.g., add the tag 'summer2018' to all products in the summer 2018 collection.)
- Enable pre-order for all products tagged with the tag you added in step 1 above.